Abstract: A method of encrypting data, in particular encrypting data in dependence on a user verification confidence level. An encryption algorithm is provided, data is input into the encryption algorithm, along with a public key and an access structure comprising the user verification confidence level. The encryption algorithm is run to output a cypher text of encrypted data, whereby the access structure is embedded into the cypher text such that only an entity satisfying the access structure can decrypt the cypher text.

Abstract: Measures, including a method, system, and computer program, for performing in-mission photogrammetry while an imaging platform is surveying a target environment. A plurality of images of the target environment are captured by the imaging platform. At the imaging platform, a representative subset of images is identified from the captured plurality of images. The imaging platform transmits the identified representative subset to a processing node. At the processing node, the transmitted representative subset is processed to generate a virtual model of the target environment.

Abstract: A multibeam antenna is provided comprising a direct radiating array, DRA, and a reflector arranged to reflect signals radiated from the DRA in a transmission mode and to reflect signals to the DRA in a reception mode. The antenna is a very high throughput satellite (VHTS) antenna providing global coverage with narrow, high gain beams.

Abstract: There is provided a method of assigning use of a bandwidth for radio communication. The method includes the following steps: generating an initial frame, the initial frame including a series of allocations; generating a further frame, the further frame including a series of allocations; repeating the step of generating a further frame to generate a matrix of allocations; shuffling at least two columns or at least two rows within the matrix; selecting one or more columns or rows in the matrix, wherein each selected column or row represents a sequence; assigning use of the bandwidth according to the one or more selected sequences; and transmitting one or more data streams on the assigned bandwidth.

Abstract: Optical Fast Fourier Transforms are described for use in photonic beamforming systems. Transmit and Receive photonic beamforming systems for use with active array antennas are described, together with digital and photonic payloads for use with such beamforming systems.

Abstract: Measures for managing satellite bearer resources of a satellite telecommunications network. A corpus of data based on historical satellite bearer resource allocations is maintained. A machine learning agent is trained with the corpus to determine a plurality of weights for use in directing satellite bearer resource management in the satellite telecommunications network. A satellite bearer resource allocation request is received. A set of features is extracted from a current environment of the satellite telecommunications network. The set of features defines currently allocated satellite bearer resources. On the basis of the determined plurality of weights and the set of features, satellite bearer resources of the satellite telecommunications network are managed to satisfy the request.

Abstract: A method of soft-decision decoding including training a machine learning agent with communication signal training data; providing to the trained machine learning agent a signal that has been received via a communications channel; operating the machine learning agent to determine respective probabilities that the received signal corresponds to each of a plurality of symbols; and, based on the determined probabilities, performing soft decision decoding on the received signal.

Abstract: A method of communicating between a rotary wing platform and a ground terminal via a satellite. The method comprises, at the rotary wing platform, receiving a forward link signal transmitted by the satellite; on the basis of the received forward link signal, estimating at least one obstruction characteristic associated with obstruction of a signal transmission path between the rotary wing platform and the satellite by one or more blades of the rotary wing platform; determining a plurality of time periods during which the at least one obstruction characteristic indicates that the signal transmission path will not be obstructed by the one or more blades of the rotary wing platform; and transmitting to the satellite a bursted carrier return link signal comprising a plurality of bursts, wherein each burst in the plurality of bursts is transmitted during one of the determined time periods.

Abstract: An Array-Fed Reflector (AFR) antenna assembly is provided comprising an AFR antenna comprising a feed array a reflector, and a mechanism for moving a position of the reflector relative to a position of the feed array such that a focal region of the reflector is movable with respect to the position of the feed array.

Abstract: An optimisation method is presented for the transmission of data along any radio frequency link which can be split into distinct transmission blocks, an example being a beam hopping system. By reordering the packets to be transmitted, it is possible to send packets either at, or nearer to, their optimal modulation and encoding configuration. This will allow for a higher bit to symbol conversion for the majority of packets and hence more data bits can be sent for the same number of symbols.

Abstract: A method of telecommunications includes the steps of receiving an encoded block having a plurality of values, dividing the received encoded block into a plurality of received segments, each received segment comprising at least two of the values, decoding each received segment by providing, for each received segment, a plurality of estimated encoded sequences, each estimated encoded sequence comprising at least two data units, merging estimated encoded sequences for consecutive segments to provide a plurality of candidate sequences, and selecting one of the plurality of candidate sequences by performing a closest fit calculation between the received encoded data block and each of the candidate sequences. The method is suitable for use in software-defined radios.

Abstract: An elongate flexible waveguide section for radio frequency signals is provided, wherein the waveguide section is corrugated in the longitudinal direction, and the waveguide section is at least partially corrugated in a circumferential direction perpendicular to the longitudinal direction. Also provided is an apparatus for connecting a VHTS antenna system to a spacecraft.

Abstract: A system and method for secure cloud computing. The cloud based processing system comprises a user interface, allowing a user to enter and edit data, a proxy server, and a cloud based processing server. The user interface sends data entered by a user to the proxy server, which sends the encrypted data to the cloud based processing server. The proxy server receives editing commands from the user interface, and sends those commands to the cloud based processing server along with the encrypted data. The cloud based processing server receives the encrypted data and editing commands, applies the editing commands to the encrypted data, and sends the edited encrypted data back to the proxy server.

Abstract: Embodiments of the present invention comprise a signal processing method and apparatus for use in a satellite payload in which an input RF signal received at a receiver antenna is modulated by using a single optical carrier at the input of an optical modulator. The optical domain signal is processed and is subsequently combined with a single unmodulated optical LO tone to provide an output RF signal for radiation by a transmitter antenna or for further digital processing by an on-board processor. This results in a clean generation of the frequency-converted RF signal at the output of the opto-electrical conversion stage.

Abstract: A maritime radar system is provided, comprising a transmitter, a receiver, and one or more processors arranged to provide range and azimuth discrimination of a detection area by performing a delay/Doppler analysis of the echo of a single beam transmitted by the transmitter and received by the receiver.

Abstract: A multibeam antenna comprises a direct radiating array (DRA) comprising a plurality of radiating elements, a reflector facing the DRA so as to reflect a field generated by the DRA, and a DRA controller configured to control the plurality of radiating elements of the DRA according to a plurality of coefficients, such that the field generated at the DRA produces a plurality of beams when reflected by the reflector. The DRA controller is configured to determine the plurality of coefficients by using a bifocal antenna model to determine a field that would be produced by a subreflector and feed horn arrangement in an equivalent bifocal antenna configured to produce the plurality of beams, and determine the plurality of coefficients required to produce a similar incident field at the surface of the reflector. A method of controlling the multibeam antenna, and corresponding computer program instructions, are also disclosed.

Abstract: This disclosure relates to a wheel assembly (1) comprising a wheel, a deformable chamber (6) containing a transition substance (15) comprising jamming particles and an interstitial gas, and an actuator (14) configured to transform the transition substance (15) between a fluid state in which the deformable chamber (6) can deform into a conformal state as the wheel encounters an obstacle during use, and a rigid state by evacuation of the interstitial gas in which the transition substance is rigidified to maintain the deformable chamber (6) in said conformal state to provide increased purchase on said obstacle.

Abstract: A first spacecraft comprises a drive mechanism. A second spacecraft comprises a valve for filling/draining the second spacecraft. The coupling assembly comprises a first connector comprising an actuating member configured to engage and open the valve and a coupling member configured to couple to the drive mechanism. A second connector comprises a stop portion and a bore for transferring fluid. Operation of the drive mechanism rotates the coupling member and the second connector together to screw the second connector onto the valve until the stop portion engages the valve, the actuating member being prevented from moving relative to the second connector to open the valve whilst the lock is in the locked state. Once the stop portion engages the valve, operation of the drive mechanism to exert a torque on the coupling member greater than a predetermined torque level moves the lock to an unlocked state wherein the actuating member is moveable relative to the second connector to engage and open the valve.

Abstract: Disclosed are a calibration system and method for correction of tracking drifts in the output section of a satellite payload and a beamforming network. The disclosed technique exploits characterisation of path gain and phase tracking drifts as deterministic errors that can be measured over spacecraft lifetime without statistical approximations, and thereafter predicted for in-orbit daily temperature variations. Also disclosed is a satellite payload for transmitting test signals to the calibration system.

Abstract: A waveguide assembly for a radio frequency (RF) signal network can include a plurality of waveguides, wherein at least two of the plurality of waveguides are integrally formed with each other. A satellite payload can include the waveguide assembly, a method of manufacturing a waveguide assembly, and a method of manufacturing a signal network. Also provided is a waveguide connector having a flange, and a plurality of ports, wherein the flange can couple to a further waveguide connector, each port of the plurality of ports being configured to interface with a respective waveguide.